Apparatus for producing glass fibers



1965 E. T. MARTIN ETAL 3,168,383

APPARATUS FOR PRODUCING GLASS FIBERS Filed Sept. 7, 1962 SUCTIONINVENTORS EARL 7.- mmzw/v Rosier F? 7/!!08410 A Tram/7 United StatesPatent 3,168,388 APPARATUS FOR PRODUCING GLASS FIBERS Earl T. Martin andRobert F. Theobald, Shelbyville, Ind., assignors to Pittsburgh PlateGlass Company, Pittsburgh, Pa., a corporation of Pennsylvania FiledSept. 7, 1962, Ser. No. 222,070 1 Claim. (Cl. 651) This inventionrelates to the production of fibers and more particularly to guiding andthreading apparatus for the fibers. Such apparatus finds particular usein the production of glass fiber products wherein glass filaments aredrawn from a source of molten glass through a plurality of laterallyspaced orifices and thereafter fed into a high velocity gaseous blastfrom a burner to make very fine fibers. In this type of operation, it ispreferable to introduce the primary fibers or filaments singly into thegaseous burner discharge and spaced apart, so they do not Weld togetherwhen softened by the high degree of heat from the burner.

In order to achieve maximum production of fibers, they are normallyspaced as close as practicable by means of a guide which supports thefibers as they are attenuated by the gaseous blast. The primary fibersor filaments are pulled from the orifices by rotation, resilientcovered, friction rolls at a predetermined rate. The usual practice isto hand thread each fiber separately into the guide upon start of theoperation, a tedious operation considering the number and size of thefilaments. The present invention is such as to simplify the threadingoperation and the time required for threading the fibers.

In accordance with this invention, the apparatus includes the source ofmolten glass, orifices from which the glass issues as streams to beattenuated into primary fibers or filaments, the pulling rolls fordrawing the filaments of glass and feeding the filaments to a hotgaseous blast and guide structure for guiding the filaments to and fromthe pulling rolls. The guide structure includes an upper guide memberinterposed between the orifices and the pulling rolls and a lower guidemember between the pulling rolls and a burner from which hot gases aredischarged to soften and produce fine fibers which are deposited onto amoving foraminous conveyor as a blanket or mat for subsequentprocessing. A comb portion of the overall guide structure is disposedbetween the orifices and the upper guide member.

The invention to be particularly described and claimed herein is thecomb portion of the guide structure which is constructed to facilitatethreading of the fibers thereinto and is also so constructed andpositioned to permit the passage of stones-a mass of material of largersize and different composition than the filamentswith ease so that thecontinuity of the process is insured.

To further understand this invention, attention is directed to theaccompanying drawing, in which;

FIG. 1 is a side view of the general arrangement for producing fibrousproducts and illustrating the comb structure of this invention in itsproper location; and

FIG. 2 is a perspective view of the comb of this application.

Referring now to the drawings, there is illustrated a feeder connectedto a source of molten glass 12 and having a plurality of laterallyspaced orifices through which streams of glass issue pulled into primaryfibers "ice or filaments 14 by a pair of pulling rolls 16 and 18. Thefilaments are held spaced by upper guide means 20 which includes a pairof members 22 and 24 each having a plurality of spaced grooves, one foreacch filament, which form openings through which the filaments 14 pass.Below the pulling rolls is a lower guide member 26 having a like numberof spacing of grooves, each to receive a filament 14 as it is fed into ahot gaseous blast from burner 28. The blast attenuates the primaryfibers and deposits the attenuated fibers as a blanket onto a movingconveyor 29 of known construction. Between the feeder 10 and the upperguide means 20 is a comb 30 of novel construction which serves to gatherthe filaments into a predetermined lateral area yet maintains eachspaced from the others for delivery to the upper guide means 20 et seq.As previously mentioned, each filament 14 is hand threaded into the comb30, a tedious job. An idler roller 31 having a cylindrical surface issupported on an axle just below the comb 30 to line up the fibers 14into a plane for delivery to the upper guide 20.

The comb 30 as particularly illustrated in FIG. 2 includes a supportingportion 32 in the form of a bar of a heat resistant metal, such asstainless steel, although the particular metal or material is not ofimportance, so long as it resists the temperatures to which it issubjected, and a plurality of teeth identified for purposes of furtherdescription as 34 and 36. The teeth 34 are of one length while the teeth36, which alternate with the teeth 34, are of a different length. Asshown, the teeth 34 are longer than the teeth 36. The teeth are spaced asuflicient distance apart to permit the free passage of a filament 14therebetween and are made of flexible metal for purposes to bedescribed.

Flexibility of at least the pins 34, i.e., the longest length pins,materially assists an operator to easily thread the filaments into thespaces between the teeth. Each pin 34 can be flexed either to the rightor to the left, as the case may be, to provide a V-shaped entrance tothe space between adjacent teeth so that the filament can be insertedinto the space. This is extremely important when the actual spacing,i.e., 0.06 inch cent-er-to-center, of the teeth is considered. Theflexibility of the teeth serves at least another useful function. Attimes, stones are discharged from the feeder. Stones are usually largerin diameter than the filaments and the spacing of the comb teeth, andare of glassy materials dilfering from that of the filaments. They maybe of the same composition as the refractory used to construct the glassmelting tank. If the stones cannot pass the comb, disruption of theprocess occurs. Breakage of the filament will occur and the glass willdischarge from the feeder without a pulling force being applied. Thisdischarging stream may interfere with other filaments and cause weldingof a group, requiring stoppage and rethreading of the filaments. Beingflexible, the teeth flex upon contact with a stone and permit it topass.

The comb of this invention has been described with particular referenceto a particular fiber forming arrangement. It could be used with otherarrangements without departing from the invention, set out in theappended claim.

We claim:

In apparatus for producing glass fibers including a source of moltenglass, a bushing having a plurality of 3 4 orifices therethrough fordischarging streams of glass from References Cited in the file of thispatent said source, means for pulling said streams of glass to UNITEDSTATES PATENTS form fibers, the improvement which comprises a comb forseparating said fibers, said comb including a plurality of 72,147,253Hassold 141 1939 spaced flexible teeth fixed at one end to a support andde- 5 276310O Holtschulte SePt' 181 1956 fining therebetween spacesterminating at the support each receiving a fiber, alternate ones ofsaid teeth being of FOREIGN PATENTS greater length than the others ofsaid teeth to permit the 17,023 at a n y 1903 fibers to be easilythreaded into said spaces. of 1902

